A portable instrument for arteriosclerosis assessment containing sensor module, acquisition board and embedded module was developed for home care in this paper. The sensor module consists of one ECG module and three pulse wave extraction modules, synchronously acquiring human ECG and pulse wave signal of carotid, radial, and dorsal, respectively. The acquisition board converts the sensor module's analog output signals into digital signals and transmits them to the embedded module. The embedded module realizes the functions including signal display, storage and the calculation and output of pulse wave velocity. The structure of the proposed portable instrument is simple, easy to use, and easy to expand. Small size, low cost, and low power consumption are also the advantages of this device. Experimental results demonstrated that the proposed portable instrument for arteriosclerosis assessment has high accuracy, good repeatability and can assess the degree of atherosclerosis appropriately.
Arteriosclerosis ; diagnosis ; Equipment Design ; Humans ; Monitoring, Ambulatory ; instrumentation

Objective To study the mechanics of improved memory alloy fixators for salvage of periprosthetic femoral fracture (PFF) after hip arthroplasty in the elderly.Methods Thirty countrymen fresh cadaveric femurs with no pathological defect,fracture,deformity or tumor were randomly divided into experimental group and control group with 15 femurs in each according to the random number table.A model of Vancouver type B1 periprosthetic femoral fracture following hip arthroplasty was induced.The fracture was treated with modified memory alloy embracing fixators in experimental group;instead general memory alloy embracing fixators in control group.All specimens were tested biomechanically.Results Under the same mechanical loading,the two groups showed respective 30％ and 48％ maximum differences in stress value and displacement.Results in three-point bending test did not differ significantly between the two groups (P ＞ 0.05),but there were significant differences in axial compression and torsion test (P ＜ 0.05 or 0.01).Conclusion The improved memory alloy embracing fixators present better resistance to compression and torsion compared to the general fixators.

Objective To investigate the clinical efficacy of surgical treatment for stage Ⅳ gastric cancer after conversion therapy.Methods The retrospective cohort study was conducted.The clinicopathological data of 50 stage Ⅳ gastric cancer patients who were admitted to the First Affiliated Hospital of Dalian Medical University between January 2012 and June 2016 were collected.All the 50 patients who were diagnosed with single distal metastasis underwent chemotherapy.After chemotherapy,21 patients with operation indication receiving gastrectomy (R0 or R1 resection) were allocated into the conversion surgery group and 29 without operation indication continuing to chemotherapy were allocated into the chenotherapy group.Patients received S-1 + oxaliplatin or S-1 + docetaxel regimen.Patients underwent open distal or total gastrectomy.Observation indicators:(1) response assessment of chemotherapy (complete remission,partial remission,stable disease and progressive disease),grading of of adverse reactions;(2) intra-and post-operative situations of conversion surgery group:operation procedures,intraoperative situations (operation time,volume of blood loss,number of lymph node dissected and surgical margin) and postoperative situations (complications and duration of hospital stay);(3)comparison of follow-up and survival between the 2 groups;(4) prognostic factors analysis affecting stage Ⅳ gastric cancer patients.Follow-up using outpatient examination,correspondence and telephone interview was performed to detect postoperative survival of patients up to September 2016.Survival time was from operation to the last follow-up or death.Measurement data with normal distribution were represented as x±s.Comparison of count data and univariate analysis were done using the chi-square test.Ordinal data were analyzed by the nonparametric test.The survival rate was calculated by the Kaplan-Meier method,and the Log-rank test was used for survival analysis.Multivariate analysis was done using the COX regression model.Results (1) Response assessment of chemotherapy:of 50 patients,24 received S-1 + oxaliplatin regimen and 26 received S-1 + docetaxel regimen.Twenty-one patients in the conversion surgery group underwent chemotherapy,with negative peritoneal metastasis,N2 and below of lymph node metastasis (No.16 lymph node disappeared or reduced),invasive depth ＜T4b and narrowing or disappeared hepatic metastasis.A median preoperative chemotherapy cycle was 4.2 cycles (range,2.0-9.0 cycles).Chemotherapy reaction of 21 patients:15 had partial remission and 6 had stable disease.Twenty-nine patients without operation indication in the chemotherapy group didn't receive surgery.The median cycle of first-line chemotherapy was 5.5 cycles (range,2.0-10.0 cycles).Chemotherapy reaction of 29 patients:13 had partial remission,11 had stable disease and 5 patient had progressive disease.Chemotherapy adverse reactions of 50 patients:26 had reduced white blood cells (WBCs),including 6 with grade Ⅲ-Ⅳ of adverse reactions;29 had reduced neutrophils,including 12 with grade Ⅲ-Ⅳ of adverse reactions;18 had anemia,including 6 with grade Ⅲ-Ⅳ of adverse reactions;12 had reduced platelets,including 2 with grade Ⅲ-Ⅳ of adverse reactions;27 had apositia,including 5 with grade Ⅲ-Ⅳ of adverse reactions;7 had stomatitis;9 had diarrhea;3 had elevated serum creatinin;4 had hand-foot syndrome;3 had abnormal sensory nerve.There was no chemotherapy-related death.(2) Intra-and post-operative situations of conversion surgery group:of 21 patients in the conversion surgery group,8 underwent radical total gastrectomy + D3 lymph node dissection,6 underwent radical distal gastrectomy + D3 lymph node dissection and 7 underwent radical distal gastrectomy + D2 lymph node dissection (including 4 combined with resection of hepatic metastatic tumors and 1 combined with radiofrequency ablation of hepatic metastatic tumor).Operation time,volume of blood loss,number of lymph node dissected and recovery time of gastrointestinal function of 21 patients were (216±31)minutes,(128±52)mL,31±8 and (3.0± 0.7)days,respectively.There were 17 patients receiving R0 resection and 4 receiving R1 resection (3 with positive gastric margin and 1 with positive hepatic margin).There was no death.Seven of 21 patients with complications were cured by conservative treatment,including 2 with pancreatic fistula,1 with intra-abdominal hemorrhage,1 with intestinal obstruction,1 with pneumonia,1 with intra-abdominal infection and 1 with wound infection.Duration of hospital stay of 21 patients was (13.0±3.0) days.(3) Comparison of follow-up and survival between the 2 groups:50 patients were followed up for 6-46 months,with a median time of 24 months.The 3-year cumulative survival rates in the conversion surgery and chemotherapy groups were respectively 33.3％ and 6.9％,with a statistically significant difference between the 2 groups (x2 =7.678,P＜0.05).Results of further analysis showed that R0 resection of 17 patients and R1 resection of 4 patients in the conversion surgery group were respecgtively (25.3±2.8)months and (8.3±0.9)months,with a statistically significant difference between the 2 groups (X2=16.242,P＜0.05).(4) Prognostic factors analysis affecting stage Ⅳ gastric cancer patients:results of univariate analysis showed that T stage,N stage,response assessment of chemotherapy,surgery after chemotherapy and degree of tumor radical resection were related factors affecting prognosis of stage Ⅳ gastric cancer patients (X2 =5.288,12.645,25.581,8.372,12.001,P＜0.05).Results of multivariate analysis showed that R1 resection after conversion therapy was an independent risk factor affecting prognosis of stage Ⅳ gastric cancer patients (HR=14.021,95％ confidence interval:1.928-10.938,P＜0.05).Conclusion Radical resection after conversion therapy can increase survival rate of stage Ⅳ gastric cancer patients,and R1 resection after conversion therapy is an independent risk factor affecting poor prognosis of stage Ⅳ gastric cancer patients.

Aim To observe the neuroprotective effect of different doses of propofol on ischemic fetal rat brain.Methods Eighteen healthy pregnant SD rats were randomly allocated into the following six groups with three rats in each.Group S: sham operation group, Group IR: ischemia/reperfusion group, Group P1~P3: different doses of propofol groups, Group B: bicuculline group.In group S and group IR, 1 ml saline solution was administered via caudal vein.In group P1~P3, 10, 30, 50 mg·kg-1 of propofol was administered via caudal vein respectively.In group B, when 50 mg·kg-1 propfol was administered via caudal vein, 5 mg·kg-1 bicuculline was injected intraperitoneally at the same time.Bilateral uterine ovarian arteries were clamped for 11 mins to make intrauterine distress model of the fetal rats.The brains of fetal rats were removed after 3 days of reperfusion.Brain sections(5 μm thick) were mounted and stained with Hematoxylin and eosin(HE).The profile of the hippocampus CA1 was evaluated under a light microscope and neuronal Lesion-index(LI) was calculated.MDA content of fetal rat brain was detected by thiobarbituric acid reaction method to determine the lipid peroxidation degree of brain.Results LI was (7.2±0.9) and MDA was (3.86±0.20) μmol·g-1 in group S.LI was 71.9±2.8 and the content of MDA was (9.10±0.45) μmol·g-1 in group IR, which increased significantly compared with those in group S(P<0.01).LI was (40.8±2.6), (21.4±1.4), (20.1±1.3) and the content of MDA was (7.32±0.41), (5.65±0.27), (5.44±0.28) μmol·g-1 in propofol groups, which decreased significantly compared with those in group IR(P<0.05).LI and the content of MDA was (51.2±2.3), (7.54±0.31) μmol·g-1 in group B,respectively, reversing partly the neuroprotevtive effect of propofl.Conclusion Propofol could protect the neurons in hippocampus CA1 region of fetal rat against intrauterine distress by reducing the concentration of MDA in the brain.

Objective:To investigate the clinical and neuroimaging features of atypical teratoid/rhabdoid tumors (AT/RT) of the central nervous system and the survival prognosis in different locations.Methods:The clinical data of 27 patients with AT/RT confirmed by biopsy or postoperative pathology in Sanbo Brain Hospital of Capital Medical University from October 2012 to September 2020 were collected, including 17 males and 10 females, aged (7.6±10.0) years, ranging from 0.2 to 39.0 years old.The clinical features and the results of the first preoperative imaging examination were retrospectively analyzed.The patients were divided into supratentorial, infratentorial and trans supratentorial and infratentorial groups according to the location.The survival time of the three groups was compared by Kaplan-Meier survival curve.Results:All patients presented with headache, including 12 cases with vomiting.There were 12 cases of supratentorial, 10 cases of infratentorial and 5 cases of supratentorial and infratentorial.There were 20 cases of cystic degeneration, 7 cases of calcification, 6 cases of hemorrhage and 13 cases of peritumoral edema.The median survival time of patients with infratentorial AT/RT was longer than that of patients with supratentorial and transtentorial AT/RT (χ 2=7.353, P=0.025). Conclusion:Central nervous system AT/RT is easy to occur in young children, and the survival time of AT/RT patients is longer.

Objective To detect attenuated plaque by using intravascular ultrasound (IVUS) in patients with acute myocardial infarction (AMI) and to investigate the influence of attenuated plaque on perioperative period of percutaneous coronary intervention (PCI). Methods Coronary angiography and IVUS were performed in 85 hospitalized patients with AMI, additional implantation of stent was employed when necessary. According to the presence or absence of attenuated plaque determined by IVUS, the patients were divided into attenuated plaque group(n=35) and non-attenuated plaque group(n=50). The perioperative IVUS findings, the blood flow classification after myocardial infarction thrombolysis (TIMI) and the postoperative peak value of creatine kinase MB (CK-MB) determined were compared between the two groups. Results Among the 85 AMI patients, attenuated plaque was detected in 35 (41.2%) and no attenuated plaque was found in 50(58.8%). No statistically significant differences in the age, sex and risk factors existed between the two groups (P>0.05). The proportion of having attenuated plaque in patients with ST segment elevation myocardial infarction (STEMI) was obviously higher than that in patients with non-STEMI (P<0.01). In performing coronary angiography, the difference in TIMI blood flow classification between the two groups was not statistically significant (P>0.05), but after balloon dilatation the TIMI grade 0-2 in theattenuated plaque group was strikingly higher than that in the non-attenuated plaque group (P=0.003). After PCI, the proportion of patients with elevated CK-MB value and higher peak value in the attenuated plaque group was remarkably higher than those in the non-attenuated plaque group (P<0.01). Conclusion The results of this study indicate that attenuated plaque can increase the incidence of no-reflow and slow reflow after PCI, which is more often seen in STEMI patients. The attenuated plaque carries significantly high risk, and the presence of attenuated plaque is helpful in predicting, the elevated extent of CK-MB value after PCI.

Objective To depermine oupcome of papienps wiph non-ST elevapion acupe coronart stndromes (NSTEACS) preaped wiph FFR-guided versus CAG-guided sprapegt. Methods From Jult 1. 2014 po Jult 30. 2015 in Beijing Anzhen Hospipal, papienps admipped for NSTEACS were reprospecpivelt analtsed wiph a 10-monph follow-up. 142 cases on CAG were furpher assessed wiph FFR ( phe FFR group). Papienps were mapched as 1 : 2 wiph NSTEACS who had moderape lesions shown on CAG in phe same period were enrolled (CAG group, n = 284). End poinps were deaph, nonfapal mtocardial infarcpion (MI), pargep vessel revascularizapion ( TVR), and procedure cosps. Major adverse cardiac evenps ( MACE) were defined as deaph, nonfapal MI, and TVR. Results Fifpt-pwo papienps (36. 6% ) in phe FFR group had FFR less phan 0. 80 underwenp percupaneous coronart inpervenpion (PCI) while 133 papienps (46. 8% ) in phe CAG group received PCI (P =0. 037). Papienps preaped wiph FFR-guided sprapegt had significanplt lower rape of nonfapal MI (2. 2% vs. 4. 5% , P =0. 040) and TVR (5. 9% vs. 11. 7% , P = 0. 046). No spapispical difference was observed in morpalipt (0. 7% vs. 1. 1% , P = 0. 682) and MACE (8. 8% vs. 14. 4% , P = 0. 085). Topal financial cosp was less in phe FFR group (P = 0. 033). Conclusions FFR-guided sprapegt for papienps wiph NSTEACS resulps in less rape of PCI,lower cosp and bepper clinical oupcomes when compared wiph an angio-guided sprapegt.

Objective To determine whether the presence of coronary collateral lfow, as evidenced by angiography, has a beneifcial effect on left ventricular function in ST-segment-elevation myocardial infarction (STEMI) treated by means of early percutaneous coronary intervention (PCI). Methods Between April 2012 to November 2013, 95 patients with STEMI treated with primary PCI successfully were analyzed. According to the Rentrop grade, these patients were divided into 2 groups:collateral circulation group (n=16) and non-collateral circulation group (n=79). The left ventricular function was evaluated within 24 hours after PCI and 30 days later. Results Comparison of 2 groups showed that collateral lfow was associated with better left ventricular ejection fraction within 24 hours and 30 days after PCI. And non-collateral lfwa was associated with more ventricular aneurysm formation. Conclusions The presence of angiographically detectable collaterals has a protective effect on left ventricular function in ST-segment-elevation myocardial infarction (STEMI) treated by primary PCI.

Magnetic susceptibility is an intrinsic physical quantity which describes the relationship between material magnetization and applied external magnetic field. Quantitative susceptibility mapping (QSM) is an MRI technology which can quantify the buck magnetic susceptibility of tissue in vivo. It is particularly effective at elucidating anatomy with paramagnetic or diamagnetic components. QSM technology is a method for solving the ill-pose problem of unconventional de-convolution of the measured tissue magnetic field with the unit magnetic dipole field to obtain the susceptibility source map. Many multi orientation scan based QSM and clinically acceptable single orientation QSM methods have been proposed to solve this ill-posed problem. In this paper, the QSM concept is introduced and the various QSM methods are systematically categorized and discussed. The aim of this paper is to summarize the current research progress of QSM, popularize the knowledge of QSM and promote the improvements and the rational application of QSM in clinical field.
Humans ; Magnetic Fields ; Magnetic Resonance Imaging ; trends ; Magnetics

Objcctive To detect the telomerase activity in rat hepatic oval cells, and to explore the relationship between telomerase expression and the proliferation and differentiation of oval cells. Methods The 2-acetamidofluorene/partial bepatectomy (2-AAF/PH) rat model was used to induce the proliferation of oval cells. Oval cells were isolated by modified collagenase perfusion and gradient centrifugation. Electron microscope exami-nation and immunofluorescence were adopted to identify oval cells. Immunohistochemistry, RT-PCR and fluores-cence quantitative PCR were used to detect the expression of telomerase in oval cells. All the data collected were analyzed by t test. Results The proliferatiun of oval cells was successfully induced by 2-AAF/PH rat model. Freshly isolated oval cells showed a large and ovoid nuclei, a small proportion of cytomplasm and a cobblestone appearance. When viewed by electron microscopy, there were few and immature organelles, and the nucleus/ cytoplasm ratio was high. Immunofluorescence staining showed that oval cells expressed OV-6, alpha-fetoprotein, cytokeratin-19, albumin and c-kit. Telomerase reverse transcriptase (TERT) was located in the nuclei of oval cells which were around the portal areas. As oval cells differentiated into small hepatocytes, the number of TERT-positive cells decreased significantly. The expression level of TERT mRNA in normal rat liver tissue was 2.27 times higher than that in LE-6 oval cells; the expression level of TERT mRNA in the isolated oval cells was 1.26 times higher than that in LE-6 oval cells. The telomerase activity decreased gradually (from △A=1.05, 1.15 to △A=0.25, 0.45) as the increase of oval cells passage (from passage 24 to passage 40) (t=17.74, 12.38, P<0.05). Conclusions Oval cells have telomerase activity. Telomerase may be indispensable for maintaining the proliferative and multi-directional differentiation abilities of oval cells.